The aim of this study was to investigate the usefulness of human embryonic kidney HEK293 cells as a model of normal cells in biotin-mediated therapy. The expression and role of sodium multivitamin transporter (SMVT) in the uptake and accumulation of free biotin, as well as cationic and neutral biotinylated PAMAM dendrimers of the fourth generation synthesized in our laboratory, were assessed in HEK293 cells in comparison to other immortalized (HaCaT) and cancer cells (HepG2, U-118 MG). The obtained data showed that a higher level of SMVT in HEK293 cells was not associated with a stronger uptake of biotin and biotinylated PAMAM dendrimers. Biotinylation increased the selective uptake of neutral dendrimers in an inversely proportional manner to the concentration used; however, the accumulation in HEK293 cells was lower than that in cells of other cell lines. The time-dependent biotin and biotinylated dendrimers uptake profiles differed significantly. Therefore, it should be assumed that the efficiency of biotinylated nanoparticles’ uptake depends on multiple cellular transport mechanisms. Toxicity tests showed significantly higher sensitivity to PAMAM conjugates for HEK293 cells than for HepG2 and HaCaT cells. Molecular modeling studies and the profile of biotin uptake suggest that not only SMVT but also monocarboxylate transporter 1 (MCT-1) may play an important role in the selective transport of biotin and biotinylated nanoparticles into cells. Due to the complexity of the problem, further studies are necessary. In summary, HEK293 cells can be considered a valuable model of normal cells in the study of biotin- targeted therapy using nanoparticles based on PAMAM dendrimers.

Fulvestrant (F), lapatinib (L), and paclitaxel (P) are hydrophobic, anticancer drugs used in the treatment of estrogen receptor (ER) and epidermal growth factor receptor (EGFR)-positive breast cancer. In this study, glycidylated PAMAM G4 dendrimers, substituted with F, L, and/or P and targeting tumor cells, were synthesized and characterized, and their antitumor activity against glioma U-118 MG and non-small cell lung cancer A549 cells was tested comparatively with human non-tumorogenic keratinocytes (HaCaT). All cell lines were ER+ and EGFR+. In addition, the described drugs were tested in the context of antinematode therapy on C. elegans. The results show that the water-soluble conjugates of G4P, G4F, G4L, and G4PFL actively entered the tested cells via endocytosis due to the positive zeta potential (between 13.57–40.29 mV) and the nanoparticle diameter of 99–138 nm. The conjugates of G4P and G4PFL at nanomolar concentrations were the most active, and the least active conjugate was G4F. The tested conjugates inhibited the proliferation of HaCaT and A549 cells; in glioma cells, cytotoxicity was associated mainly with cell damage (mitochondria and membrane transport). The toxicity of the conjugates was proportional to the number of drug residues attached, with the exception of G4L; its action was two- and eight-fold stronger against glioma and keratinocytes, respectively, than the equivalent of lapatinib alone. Unfortunately, non-cancer HaCaT cells were the most sensitive to the tested constructs, which forced a change in the approach to the use of ER and EGFR receptors as a goal in cancer therapy. In vivo studies on C. elegans have shown that all compounds, most notably G4PFL, may be potentially useful in anthelmintic therapy.

In this study, we hypothesized that biotinylated and/or glycidol-flanked fourth-generation polyamidoamine (PAMAM G4) dendrimers could be a tool for efficient drug transport into glioma and liver cancer cells. For this purpose, native PAMAM (G4) dendrimers, biotinylated (G4B), glycidylated (G4gl), and biotinylated and glycidylated (G4Bgl), were synthesized, and their cytotoxicity, uptake, and accumulation in vitro and in vivo were studied in relation to the transport mediated by the sodium-dependent multivitamin transporter (SMVT). The studies showed that the human temozolomide-resistant glioma cell line (U-118 MG) and hepatocellular carcinoma cell line (HepG2) indicated a higher amount of SMVT than human HaCaT keratinocytes (HaCaTs) used as a model of normal cells. The G4gl and G4Bgl dendrimers were highly biocompatible in vitro (they did not affect proliferation and mitochondrial activity) against HaCaT and U-118 MG glioma cells and in vivo (against Caenorhabditis elegans and Wistar rats). The studied compounds penetrated efficiently into all studied cell lines, but inconsistently with the uptake pattern observed for biotin and disproportionately for the level of SMVT. G4Bgl was taken up and accumulated after 48 h to the highest degree in glioma U-118 MG cells, where it was distributed in the whole cell area, including the nuclei. It did not induce resistance symptoms in glioma cells, unlike HepG2 cells. Based on studies on Wistar rats, there are indications that it can also penetrate the blood–brain barrier and act in the central nervous system area. Therefore, it might be a promising candidate for a carrier of therapeutic agents in glioma therapy. In turn, visualization with a confocal microscope showed that biotinylated G4B penetrated efficiently into the body of C. elegans, and it may be a useful vehicle for drugs used in anthelmintic therapy.

Glioblastoma multiforme therapy remains a significant challenge since there is a lack of effective treatment for this cancer. As most of the examined gliomas express or overexpress cyclooxygenase-2 (COX-2) and peroxisome proliferator-activated receptors γ (PPARγ), we decided to use these proteins as therapeutic targets. Toxicity, antiproliferative, proapoptotic, and antimigratory activity of COX-2 inhibitor (celecoxib—CXB) and/or PPARγ agonist (Fmoc-L-Leucine—FL) was examined in vitro on temozolomide resistant U-118 MG glioma cell line and comparatively on BJ normal fibroblasts and immortalized HaCaT keratinocytes. The in vivo activity of both agents was studied on C. elegans nematode. Both drugs effectively destroyed U-118 MG glioma cells via antiproliferative, pro-apoptotic, and anti-migratory effects in a concentration range 50–100 µM. The mechanism of action of CXB and FL against glioma was COX-2 and PPARγ dependent and resulted in up-regulation of these factors. Unlike reports by other authors, we did not observe the expected synergistic or additive effect of both drugs. Comparative studies on normal BJ fibroblast cells and immortalized HaCaT keratinocytes showed that the tested drugs did not have a selective effect on glioma cells and their mechanism of action differs significantly from that observed in the case of glioma. HaCaTs did not react with concomitant changes in the expression of COX-2 and PPARγ and were resistant to FL. Safety tests of repurposing drugs used in cancer therapy tested on C. elegans nematode indicated that CXB, FL, or their mixture at a concentration of up to 100 µM had no significant effect on the entire nematode organism up to 4th day of incubation. After a 7-day treatment, CXB significantly shortened the lifespan of C. elegans at 25–400 µM concentration and body length at 50–400 µM concentration.

Systemic anticancer therapy causes a number of side effects; therefore, local drug release devices may play an important role in this area. In this study, we developed polyurethane-dendrimer foams containing different amounts of third-generation poly (amidoamine) dendrimers (PAMAM G3) to evaluate their ability to encapsulate and release the model anticancer drug doxorubicin (DOX), as well as their biocompatibility and effectiveness against normal and cancer cells in vitro. PU–PAMAM foams containing 10–50 wt% PAMAM G3 were prepared using glycerin-based polyether polyol and castor oil as co-components. Structural and rheological analyses revealed that foams containing up to 20 wt% PAMAM G3 exhibited a well-developed porous structure, while higher dendrimer loadings (≥30 wt%) led to irregular cell shapes, pore coalescence, and thinning of cell walls, and indicated a gradual loss of structural integrity. Rheological creep–recovery measurements confirmed the structural findings: moderate PAMAM G3 incorporation (≤20 wt%) increased both the instantaneous and delayed elastic modulus (E₁ ≈ 130–140 kPa; E₂ ≈ 80 kPa) and enhanced elastic recovery, reflecting improved cross-link density and foam stability. Higher dendrimer contents (30–50 wt%) caused a decline in these parameters and higher viscoelastic compliance, indicating a softer, less stable structure. The DOX loading capacity and encapsulation efficiency increased with PAMAM G3 content, reaching maximum values of 35% and 51% for 30–40 wt% PAMAM G3, respectively. However, the most sustained DOX release profiles were observed for matrices containing 20 wt% PAMAM G3. Analysis of cumulative release and kinetic modeling revealed a transition from diffusion-controlled release at low PAMAM contents to burst-dominated release at higher dendrimer loadings. Importantly, matrices containing 10–20 wt% PAMAM G3 also indicated selective anticancer action against squamous cell carcinoma (SCC-15) compared to non-cancerous human keratinocytes (HaCaT). Moreover, the DOX they released effectively destroyed cancer cells. Overall, PU–PAMAM foams containing 10–20 wt% PAMAM G3 provide the most balanced combination of structural stability, controlled drug release, and cytocompatibility. These materials therefore represent a promising platform as passive carriers in drug delivery systems (DDSs), such as local implants, anticancer patches, or bioactive wound dressings.

There is growing interest in local drug delivery systems that release their payload in a controlled manner directly at the implantation site. Such systems are particularly valuable in solid tumors, chronic wounds and infections, where systemic administration is constrained by poor tissue penetration and dose-limiting side effects. In this study, hydroxylated poly(amidoamine) (PAMAM) G3 dendrimers were incorporated into polyurethane foams (PU) as multifunctional polyol components to obtain hybrid porous matrices. Surface polyhydroxylation of amine-terminated PAMAM G3 via glycidol ring-opening introduced hydroxyl functionalities that enabled integration of the modified dendrimer into the PU network. Morphological analysis by scanning electron microscopy (SEM) and micro-computed tomography (µCT) confirmed a well-defined cellular architecture without macroscopic defects upon dendrimer incorporation. The modified material exhibited reduced apparent density and increased water absorption compared with the reference PU foam. Rheological creep–recovery analysis demonstrated enhanced delayed elasticity and reduced permanent deformation in the dendrimer-modified matrix, reflecting improved viscoelastic recovery. Mass balance analysis showed higher encapsulation efficiency for the dendrimer-modified foam (34.9%) than for the reference material (29.7%). Despite this higher loading, the cumulative release of doxorubicin (DOX) over 100 h in phosphate-buffered saline (PBS) (pH 7.4, 37 °C) was lower for the modified system (7.0%) than for the reference matrix (15.8%), and the initial burst release after 30 min was six-fold lower, indicating enhanced drug retention and the potential for prolonged release. Biological studies showed that the matrices were non-toxic and highly biocompatible towards human SCC-15 and HaCaT cells in vitro and in the Caenorhabditis elegans model in vivo, whereas DOX released from the matrices effectively killed cancer cells at extract concentrations as low as 3%. These results show that hydroxylated PAMAM G3 acts as a structural modifier of PU foams capable of modulating drug retention and release, and therefore use of dendrimeric matrix as a drug carrier in local therapy is worth considering.